Integrated heat exchanger and diffuser

ABSTRACT

The present invention discloses an apparatus including: a blower fan, the blower fan having multiple blades; a diffuser attached to a housing of the blower fan; diffuser vanes located in the diffuser, wherein the diffuser vanes are also fins for a heat exchanger.

BACKGROUND OF THE INVENTION

1Field of the Invention

The present invention relates to a field of mobile computers and, more specifically, to a device for integrating a heat exchanger and a diffuser in a blower fan for a notebook computer.

2. Discussion of Related Art

A typical mobile computer includes a blower fan and a heat exchanger.

A need exists for improving a thermal solution for the notebook computer within the constraints of space occupied and cost of manufacturing and assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an integrated heat exchanger and diffuser according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

In the following description, numerous details, such as specific materials, dimensions, and processes, are set forth in order to provide a thorough understanding of the present invention. However, one skilled in the art will realize that the invention may be practiced without these particular details. In other instances, well-known semiconductor equipment and processes have not been described in particular detail so as to avoid obscuring the present invention.

The present invention describes an integrated heat exchanger and diffuser for a mobile computer.

A mobile computer, such as a notebook computer, may include various electrical components or devices, such as a microprocessor, a hard drive, or a power supply that may generate a considerable amount of heat during operation. The waste heat must be adequately dissipated to ensure proper and reliable functioning of the mobile computer.

As shown in an embodiment of the present invention in FIG. 1, a blower fan 10 may be enclosed within a casing or housing 20. The blower fan 10 may include a shaft or spindle 30 that spins to rotate a rotor 35. The rotor 35 includes a hub with multiple blades 40 that point towards a periphery of the blower fan 10. In an embodiment of the present invention, the rotor may have 13-15 blades.

In an embodiment of the present invention, the hub and blades 40 may occupy a circular area with a diameter of about 40-120 mm. In an embodiment of the present invention, the circular area in which the hub and blades 40 rotate may have a vertical clearance of about 5-20 mm.

The blower fan 10 may have an inlet (not shown) above or below the rotor 35. The inlet may include a circular or annular opening equivalent to about 40-80% of the circular area occupied by the hub and the blades.

The scroll area 55 of the casing or housing 20 may wrap about 200-250 degrees around the periphery of the blower fan 10 with a gap 53 and then open up into an outlet 52 that ends with a sharp or rounded tongue 57 on the downstream side.

In an embodiment of the present invention as shown in FIG. 1, the blower fan 10 may include a diffuser 50 located adjacent to the outlet 52 of the blower fan 10. The diffuser 50 may be attached to or integrated with the casing or housing 20 at the outlet 52 or discharge side of the blower fan 10. The blower fan 10 may operate with a constant speed or with variable speed. The blower fan 10 may direct a stream of air 70 from the outlet 52 laterally through the diffuser 50.

In an embodiment of the present invention, the diffuser 50 may spread or flare out such that a cross-sectional area at a diffuser entrance (or blower fan outlet) 52 is smaller than a cross-sectional area at a diffuser exit 54. Consequently, the diffuser 50 may reduce a velocity of the stream of air 70.

In an embodiment of the present invention as shown in FIG. 1, diffuser vanes 60A, 60B may be located in the diffuser 50 of the blower fan 10. The diffuser vanes 60A, 60B may convert a volumetric air 70 flow with a linear velocity into a static pressure or head.

The diffuser vanes 60A, 60B may have rigid sidewalls. In an embodiment of the present invention, the cross-section of the diffuser vanes 60A, 60B may be solid.

The external surfaces of the diffuser vanes 60A, 60B may guide and deflect one or more streams of air 70. The diffuser vanes 60A, 60B may have a pressure side 61 and a suction side 62. In an embodiment of the present invention, the diffuser vanes 60A, 60B are configured so that the flow of air 70 does not separate from the suction side 62. In an embodiment of the present invention, the flow of air 70 will not separate from the suction side 62 of the diffuser vanes 60A, 60B if an angular deviation is 6 degrees or less. In an embodiment of the present invention, the diffuser vanes 60A, 60B may include a combination of straight segments 63 and curved segments 64.

In an embodiment of the present invention, the diffuser vanes 60A, 60B are configured so that no more than one diffuser vane 60 will line up with a blade 40 near the diffuser entrance (or blower fan outlet) 52 at any given time during operation of the blower fan 10. The blade 40 will come close to the diffuser vane 60A, 60B at the diffuser entrance (or blower fan outlet) 52 in a crescent-shaped approach zone which is wider towards the upstream side 56A and narrower towards the downstream side 56B.

In an embodiment of the present invention, the blower fan 10 may be integrated with the heat exchanger 110. In an embodiment of the present invention, the heat exchanger 110 may be attached to the blower fan 10 exit which is external to the fan housing 20. In an embodiment of the present invention, the fan housing 20 itself may be used as a heat exchanger 110 surface.

In an embodiment of the present invention, the diffuser vanes 60A, 60B may be arranged in a cascading layout 65 in the diffuser 55. One end of the diffuser vanes 60A, 60B may extend towards the scroll area 55 of the casing or housing 20 and be located adjacent to the blower fan outlet 52. Starting adjacent to the discharge side of the blower fan 10, the diffuser vanes 60A, 60B may extend across the diffuser 55 towards and beyond the heat exchanger 110 thus also becoming fins of the heat exchanger 110. In an embodiment of the present invention, a spacing 67 between adjacent diffuser vanes 60A, 60B may increase as the diffuser vanes 60A, 60B become farther away from the blower fan 10.

In an embodiment of the present invention, some of the diffuser vanes are interstitial vanes 60D that are located in the diffuser 50 far away from the scroll area 55. 100211 In an embodiment of the present invention, all of the diffuser vanes 60A are also fins of the heat exchanger 110.

In an embodiment of the present invention, some of the diffuser vanes 60B are not fins of the heat exchanger 110.

In an embodiment of the present invention, some of the fins 60C of the heat exchanger 110 are not diffuser vanes.

Integrating the heat exchanger 110 and the diffuser 50 (as well as the blower fan housing 20) will reduce the system real estate required to implement a thermal solution for the mobile computer.

The diffuser vanes 60A, 60B may be fabricated out of a material with a high thermal conductivity. In an embodiment of the present invention, the diffuser vanes 60 may be made from Copper or Aluminum.

In an embodiment of the present invention, the integrated heat exchanger 110 and diffuser 50 (with shared fins and diffuser vanes 60A) may further be coupled to an actively cooled device 80, such as a heat pipe, heat plate, heat sink, or heat spreader. The diffuser vanes 60A (of the diffuser 50) may act or serve as fins (of the heat exchanger 110), thus allowing for a more compact and efficient design of the overall thermal solution for the mobile computer.

An embodiment of the present invention improves recovery of a dynamic pressure head of the flow in the blower fan 10. In an embodiment of the present invention, the diffuser vanes 60A, 60B may result in a potential recovery of the dynamic head equivalent to about 25-50% of the pressure rise in the blower fan 10.

By combining the diffuser vanes 60A (of the diffuser 50) with the fins (of the heat exchanger 110), the passages between the fins of the heat exchanger 110 will have access to the high velocity air flow emanating from the blades 40 of the blower fan 10 (manifested as a static pressure).

Consequently, integrating the heat exchanger 110 and the blower fan housing 20 more compactly will also improve performance by increasing system airflow without degrading acoustics.

In an embodiment of the present invention, the blower fan 10 design and diffuser 50 layout are configured and integrated so that the acoustics of the blower fan 10 will be manageable and not degraded. Other factors to be considered include number of blades 40, number of diffuser vanes 60A 60B, ratio of blades to diffuser vanes, blower fan speed, gap 53 in scroll area, width 56A, 56B of the crescent-shaped approach zone, and spacing between adjacent diffuser vanes 60A, 60B.

Many embodiments and numerous details have been set forth above in order to provide a thorough understanding of the present invention. One skilled in the art will appreciate that many of the features in one embodiment are equally applicable to other embodiments. One skilled in the art will also appreciate the ability to make various equivalent substitutions for those specific materials, processes, dimensions, concentrations, etc. described herein. It is to be understood that the detailed description of the present invention should be taken as illustrative and not limiting, wherein the scope of the present invention should be determined by the claims that follow. 

1. An apparatus comprising: a blower fan, said blower fan having multiple blades; a diffuser attached to a housing of said blower fan; diffuser vanes disposed in said diffuser, wherein said diffuser vanes comprise fins for a heat exchanger.
 2. The apparatus of claim 1 wherein said diffuser has a cross-sectional area that is smaller at an entrance than at an exit.
 3. The apparatus of claim 1 wherein spacings between said diffuser vanes increase as said diffuser vanes become farther away from said blower fan.
 4. The apparatus of claim 1 wherein said diffuser vanes include a combination of straight segments and curved segments.
 5. The apparatus of claim 1 wherein one end of said diffuser vanes extend towards a scroll area of said blower fan.
 6. The apparatus of claim 1 wherein other diffuser vanes that are not fins of said heat exchanger are also disposed in said diffuser.
 7. The apparatus of claim 1 wherein said heat exchanger comprises other fins that are not diffuser vanes.
 8. The apparatus of claim 1 wherein no more than one blade will line up with said diffuser vanes at any given time.
 9. The apparatus of claim 1 wherein said diffuser vanes are made from a material with a high thermal conductivity.
 10. An apparatus comprising: a heat exchanger; a diffuser integrated with said heat exchanger; fins disposed on said heat exchanger, wherein said fins are also diffuser vanes disposed on said diffuser.
 11. The apparatus of claim 10 further comprising a blower fan, said blower fan having a housing attached to said diffuser.
 12. The apparatus of claim 10 wherein said diffuser vanes are made from a material with a high thermal conductivity.
 13. The apparatus of claim 10 wherein said diffuser vanes include a combination of straight segments and curved segments. 